HP-UX SNAplus2 CPI-C Programmer's Guide (June 2003)

Concepts

What Is CPI-C?

Chapter 1 35

Figure 1-1 Communication between Programs

Logical Unit 6.2

Each program is associated with a logical unit (LU), which is the

program's access point into the network. CPI-C uses LU type 6.2, which

supports peer-to-peer communications between LUs. Several programs

can be associated with the same LU.

Sessions

Before two programs can communicate, their LUs must be connected

through an LU-to-LU session—a logical connection between the two

LUs. The session is established using a particular mode—a set of

networking characteristics that determines how the LUs use the session.

An LU type 6.2 can have multiple sessions (two or more concurrent

sessions with different partner LUs) and parallel sessions (two or more

concurrent sessions with the same partner LU). During conﬁguration,

the System Administrator or user determines how many sessions a

particular LU supports and whether the LU supports parallel sessions.

Program A

Program B

LU1

LU2

Session

Conversation